392 



SYSTEMATIC BOTANY. 



the low type of structure of the floral envelopes ; but there is a general 

 tendency to union of the sexes here, and a difference in the position of 



Fig. 478. 



Fig. 477. 



Fig. 476. A Date, with half the pericarp removed (c) to show the seed and embryo (a:). 

 Fig. 477. Section of the fruit of the Cocoa-nut Palm: x, the shell of the nut. 

 Fig. 478. Trunk and foliage of a species of Areca. 



the embryo within the perisperm not to dwell upon the wide diversity 

 of general structure and habit. The regular ternary arrangement of the 

 flowers, the 6 stamens, and the 3-carpellary superior ovary approximate 

 this family to the Liliacese, in which, however, the habit differs in almost 

 every respect, besides the great diversity of the fruits and seeds. The 

 floral formula of a perfect Palm flower is thus that of a typical Monocotyle- 

 don, but variations occur from suppression of parts and in accordance 

 with the relative position of the bracteoles, &c. The inflorescence of the 

 Palms is in some cases axillary, allowing of indefinite growth of the 

 trunk by the terminal bud ; in other cases it is terminal, and the flowering 

 of the plant then puts a period to the term of growth (sometimes as much 

 as 20 years), the trunk dying after the ripening of the fruit (like the main 

 stem of the Agave}, but occasionally perpetuating itself by subterranean 

 axillary suckers. Sometimes the axillary inflorescence breaks out from 

 above the cicatrix of a long-fallen leaf, on the bare part of the stem. The 

 flowers are generally very numerous ; it is said that the male inflorescence of 

 the Date may bear 12,000 flowers, and that a bunch of some of the South- 

 American Palms will bear 3000 fruits. In Alfonsia amygdalina 207,000 

 flowers have been computed on a single spadix, or 600,000 on one 

 plant ! There is very considerable apparent variety of form and structure 



